US President Barack Obama
US President Barack Obama

After hosting the APEC summit in Hawaii, President Barack Obama next week makes a long-delayed visit to key U.S. ally Australia. The two countries are expected to formally announce an agreement for expanded U.S. access to Australian military bases.

President Obama was to have visited Australia last year, but twice had to postpone amid debate over health care in the United States, and because of the oil spill in the Gulf of Mexico.

Australia is one of five U.S. treaty allies in the region, and is also one of nine countries involved in negotiations to create a new Trans-Pacific Partnership.       

Obama's one-day visit coincides with the 60th anniversary of the ANZUS (Australia, New Zealand, U.S.) Treaty of 1951 that established shared security commitments.

In addition to Canberra, where he addresses Parliament, the president will stop in Darwin, the scene of some of the largest Japanese air raids of World War II.

The United States and Australia have extremely close military and intelligence ties.  Australia has troops in Afghanistan.  Obama is expected to pay tribute to Australian soldiers killed and wounded in a recent attack there.

The groundwork for the military agreement was set during talks between U.S. and Australian defense officials in recent months.  It will give greater U.S. military access to bases in Western Australia and allow for pre-positioning of equipment.

Earnest Bower of the Center for Strategic and International Studies:

"This is a big deal.  Australians have polled 55 percent in favor of supporting American basing in Australia.  This is sort of a unique time across Asia, where the U.S. security presence is very much welcomed to balance what is perceived as some recent Chinese aggression particularly in the South China Sea, also in the Senkakus and Diaoyus up north," he said.

Regional experts say Australia will figure large as the United States goes through a military force posture review, and decisions are made about the U.S. military presence in the Asia-Pacific and its cost.

Australian Ambassador to the United States Kim Beazley spoke about U.S.-Australian security cooperation, and the ANZUS alliance in a recent interview with the Southeast Asia Program of the Center for Strategic and International Studies.

"The ANZUS alliance is the one structure set up during the course of the Cold War, as part of the U.S. extended deterrence system, where the engagement between the United States and the other treaty partner has intensified since the end of the Cold War as opposed to being wandering around looking for a mission and perhaps falling by the wayside, which has been the fate of so many others," Beazley said.

In a recent speech to the World Affairs Councils of America conference in Washington, Deputy Secretary of State William Burns said a central message of Mr. Obama's Asia-Pacific trip is to underscore the U.S. security as well as economic commitment in the Pacific.

"As we look to the future, we start from a position of strength.  America is a resident diplomatic, military and economic power in the Pacific, and, as Secretary Clinton says, we are there to stay.  The foundation of our policy remains our historical alliances with Japan, South Korea, Australia, the Philippines, and Thailand, which is our oldest treaty partner," Burns said.

Burns says said the United States has an interest in ensuring freedom of navigation and open shipping routes, and notes that ASEAN countries, and China, have agreed on the need for a code of conduct.

Australia's Prime Minister Julia Gillard met with President Obama earlier this year at the White House.  The two were photographed tossing an Australian football in the Oval Office, and the prime minister accompanied Obama on a visit to a local school classroom.

After his one day visit to Australia, President Obama flies to Bali and the East Asia Summit.  There he will hold a number of bilateral meetings, including with China's President Hu Jintao, and one expected with Russian President Dmitry Medvedev.

Obama will carry the same message he delivered to leaders at the APEC summit, that the United States intends to be a reliable economic partner, and views the Asia-Pacific as the most dynamic part of the world for decades to come, and a region where stability is crucial.